I do a little differently, I remove the blind nuts, put masking tape under the wood beam and fill the holes with 2 or 3 hour epoxy, refilling as it soaks out into the wood. It will soak up quite a bit, then next day just re-drill as if there were never any previous holes. If you overfill you'll have a hump that is difficult to remove. I do the same with firewalls where I change my mind or change engine mounts.

Richard, here's one where I used your method to replace a Saito 1.00 with a Saito .80.